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Yang G, Zhou R, Guo X, Yan C, Lei J, Shi Y. Structural basis of γ-secretase inhibition and modulation by small molecule drugs. Cell 2020; 184:521-533.e14. [PMID: 33373587 DOI: 10.1016/j.cell.2020.11.049] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 10/14/2020] [Accepted: 11/24/2020] [Indexed: 01/01/2023]
Abstract
Development of γ-secretase inhibitors (GSIs) and modulators (GSMs) represents an attractive therapeutic opportunity for Alzheimer's disease (AD) and cancers. However, how these GSIs and GSMs target γ-secretase has remained largely unknown. Here, we report the cryoelectron microscopy (cryo-EM) structures of human γ-secretase bound individually to two GSI clinical candidates, Semagacestat and Avagacestat, a transition state analog GSI L685,458, and a classic GSM E2012, at overall resolutions of 2.6-3.1 Å. Remarkably, each of the GSIs occupies the same general location on presenilin 1 (PS1) that accommodates the β strand from amyloid precursor protein or Notch, interfering with substrate recruitment. L685,458 directly coordinates the two catalytic aspartate residues of PS1. E2012 binds to an allosteric site of γ-secretase on the extracellular side, potentially explaining its modulating activity. Structural analysis reveals a set of shared themes and variations for inhibitor and modulator recognition that will guide development of the next-generation substrate-selective inhibitors.
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Affiliation(s)
- Guanghui Yang
- Beijing Advanced Innovation Center for Structural Biology and Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China; State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Rui Zhou
- Beijing Advanced Innovation Center for Structural Biology and Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xuefei Guo
- Beijing Advanced Innovation Center for Structural Biology and Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Chuangye Yan
- Beijing Advanced Innovation Center for Structural Biology and Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jianlin Lei
- Technology Center for Protein Sciences, Ministry of Education Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yigong Shi
- Beijing Advanced Innovation Center for Structural Biology and Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China; Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Xihu District, Hangzhou 310024, Zhejiang Province, China; Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Xihu District, Hangzhou 310024, Zhejiang Province, China.
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Güner G, Lichtenthaler SF. The substrate repertoire of γ-secretase/presenilin. Semin Cell Dev Biol 2020; 105:27-42. [PMID: 32616437 DOI: 10.1016/j.semcdb.2020.05.019] [Citation(s) in RCA: 101] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 05/17/2020] [Accepted: 05/25/2020] [Indexed: 12/09/2022]
Abstract
The intramembrane protease γ-secretase is a hetero-tetrameric protein complex with presenilin as the catalytic subunit and cleaves its membrane protein substrates within their single transmembrane domains. γ-Secretase is well known for its role in Notch signalling and in Alzheimer's disease, where it catalyzes the formation of the pathogenic amyloid β (Aβ) peptide. However, in the 21 years since its discovery many more substrates and substrate candidates of γ-secretase were identified. Although the physiological relevance of the cleavage of many substrates remains to be studied in more detail, the substrates demonstrate a broad role for γ-secretase in embryonic development, adult tissue homeostasis, signal transduction and protein degradation. Consequently, chronic γ-secretase inhibition may cause significant side effects due to inhibition of cleavage of multiple substrates. This review provides a list of 149 γ-secretase substrates identified to date and highlights by which expeirmental approach substrate cleavage was validated. Additionally, the review lists the cleavage sites where they are known and discusses the functional implications of γ-secretase cleavage with a focus on substrates identified in the recent past, such as CHL1, TREM2 and TNFR1. A comparative analysis demonstrates that γ-secretase substrates mostly have a long extracellular domain and require ectodomain shedding before γ-secretase cleavage, but that γ-secretase is also able to cleave naturally short substrates, such as the B cell maturation antigen. Taken together, the list of substrates provides a resource that may help in the future development of drugs inhibiting or modulating γ-secretase activity in a substrate-specific manner.
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Affiliation(s)
- Gökhan Güner
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany; Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, 81675, Munich, Germany
| | - Stefan F Lichtenthaler
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany; Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, 81675, Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
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3
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van Putten JPM, Strijbis K. Transmembrane Mucins: Signaling Receptors at the Intersection of Inflammation and Cancer. J Innate Immun 2017; 9:281-299. [PMID: 28052300 DOI: 10.1159/000453594] [Citation(s) in RCA: 170] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 11/19/2016] [Indexed: 12/18/2022] Open
Abstract
Mucosal surfaces line our body cavities and provide the interaction surface between commensal and pathogenic microbiota and the host. The barrier function of the mucosal layer is largely maintained by gel-forming mucin proteins that are secreted by goblet cells. In addition, mucosal epithelial cells express cell-bound mucins that have both barrier and signaling functions. The family of transmembrane mucins consists of diverse members that share a few characteristics. The highly glycosylated extracellular mucin domains inhibit invasion by pathogenic bacteria and can form a tight mesh structure that protects cells in harmful conditions. The intracellular tails of transmembrane mucins can be phosphorylated and connect to signaling pathways that regulate inflammation, cell-cell interactions, differentiation, and apoptosis. Transmembrane mucins play important roles in preventing infection at mucosal surfaces, but are also renowned for their contributions to the development, progression, and metastasis of adenocarcinomas. In general, transmembrane mucins seem to have evolved to monitor and repair damaged epithelia, but these functions can be highjacked by cancer cells to yield a survival advantage. This review presents an overview of the current knowledge of the functions of transmembrane mucins in inflammatory processes and carcinogenesis in order to better understand the diverse functions of these multifunctional proteins.
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Affiliation(s)
- Jos P M van Putten
- Department of Infectious Diseases and Immunology, Utrecht University, Utrecht, The Netherlands
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Aberrant glycosylation as biomarker for cancer: focus on CD43. BIOMED RESEARCH INTERNATIONAL 2014; 2014:742831. [PMID: 24689054 PMCID: PMC3943294 DOI: 10.1155/2014/742831] [Citation(s) in RCA: 278] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 12/10/2013] [Indexed: 11/23/2022]
Abstract
Glycosylation is a posttranslational modification of proteins playing a major role in cell signalling, immune recognition, and cell-cell interaction because of their glycan branches conferring structure variability and binding specificity to lectin ligands. Aberrant expression of glycan structures as well as occurrence of truncated structures, precursors, or novel structures of glycan may affect ligand-receptor interactions and thus interfere with regulation of cell adhesion, migration, and proliferation. Indeed, aberrant glycosylation represents a hallmark of cancer, reflecting cancer-specific changes in glycan biosynthesis pathways such as the altered expression of glycosyltransferases and glycosidases. Most studies have been carried out to identify changes in serum glycan structures. In most cancers, fucosylation and sialylation are significantly modified. Thus, aberrations in glycan structures can be used as targets to improve existing serum cancer biomarkers. The ability to distinguish differences in the glycosylation of proteins between cancer and control patients emphasizes glycobiology as a promising field for potential biomarker identification. In this review, we discuss the aberrant protein glycosylation associated with human cancer and the identification of protein glycoforms as cancer biomarkers. In particular, we will focus on the aberrant CD43 glycosylation as cancer biomarker and the potential to exploit the UN1 monoclonal antibody (UN1 mAb) to identify aberrant CD43 glycoforms.
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Metalloproteinases and their natural inhibitors in inflammation and immunity. Nat Rev Immunol 2013; 13:649-65. [PMID: 23969736 DOI: 10.1038/nri3499] [Citation(s) in RCA: 374] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Over the past 50 years, steady growth in the field of metalloproteinase biology has shown that the degradation of extracellular matrix components represents only a fraction of the functions performed by these enzymes and has highlighted their fundamental roles in immunity. Metalloproteinases regulate aspects of immune cell development, effector function, migration and ligand-receptor interactions. They carry out ectodomain shedding of cytokines and their cognate receptors. Together with their endogenous inhibitors TIMPs (tissue inhibitor of metalloproteinases), these enzymes regulate signalling downstream of the tumour necrosis factor receptor and the interleukin-6 receptor, as well as that downstream of the epidermal growth factor receptor and Notch, which are all pertinent for inflammatory responses. This Review discusses the metalloproteinase family as a crucial component in immune cell development and function.
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Intracellular patterns of sialophorin expression define a new molecular classification of breast cancer and represent new targets for therapy. Br J Cancer 2013; 110:146-55. [PMID: 24281005 PMCID: PMC3887278 DOI: 10.1038/bjc.2013.526] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 08/09/2013] [Accepted: 08/13/2013] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Sialophorin is a transmembrane sialoglycoprotein. Normally, the molecule is only produced by white blood cells where it regulates functions such as intercellular adhesion, intracellular signalling, apoptosis, migration and proliferation. METHODS Normal breast tissue and primary breast tumours were analysed by immunohistochemistry for sialophorin expression. The sialophorin-positive breast cancer cell line MCF7 was engineered to stably express either non-targeted or sialophorin-targeted small interfering RNA (siRNA). Assays were then performed in vitro to assess apoptosis, intracellular adhesion, transendothelial migration and cytotoxicity. An orthotopic mouse model assayed ability to produce tumours in vivo. RESULTS Normal breast epithelial cells exhibit expression of the N-terminal domain of sialophorin in the cytoplasm but not the nucleus. The majority of these normal cells are also negative for expression of the C-terminal domain. In contrast, malignant breast epithelial cells exhibit N-terminal expression both in the cytoplasm and nucleus and the majority express the C-terminus in the nucleus. Using differential patterns of intracellular expression of the N and C termini of sialophorin, we define six subtypes of breast cancer that are independent of histological and receptor status classification. Targeting sialophorin with siRNA resulted in the MCF7 breast cancer cell line exhibiting increased homotypic adhesion, decreased transendothelial migration, increased susceptibility to apoptosis, increased vulnerability to lysis by natural killer cells and decreased ability to produce tumours in mice. CONCLUSION Our results indicate that intracellular patterns of sialophorin expression define a new molecular classification of breast cancer and that sialophorin represents a novel therapeutic target.
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Camacho-Concha N, Olivos-Ortiz A, Nuñez-Rivera A, Pedroza-Saavedra A, Gutierrez-Xicotencatl L, Rosenstein Y, Pedraza-Alva G. CD43 promotes cells transformation by preventing merlin-mediated contact inhibition of growth. PLoS One 2013; 8:e80806. [PMID: 24260485 PMCID: PMC3832598 DOI: 10.1371/journal.pone.0080806] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Accepted: 10/08/2013] [Indexed: 12/11/2022] Open
Abstract
In normal tissues, strict control of tissue size is achieved by regulating cell numbers. The mechanism that controls total cell number is known as contact inhibition of growth and it depends on the NF2/Merlin pathway. Negative regulation of this pathway by deleterious mutations or by oncogenes results in cell transformation and tumor progression. Here we provide evidence that the CD43 sialomucin cooperates with oncogenic signals to promote cell transformation by abrogating the contact inhibition of growth through a molecular mechanism that involves AKT-dependent Merlin phosphorylation and degradation. Accordingly, inhibition of endogenous CD43 expression by RNA interference in lung, cervix and colon human cancer cells impaired tumor growth in vivo. These data underscore a previously unidentified role for CD43 in non-hematopoietic tumor progression.
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Affiliation(s)
- Nohemi Camacho-Concha
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Amiel Olivos-Ortiz
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Alfredo Nuñez-Rivera
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Adolfo Pedroza-Saavedra
- Centro de Investigación Sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México
| | - Lourdes Gutierrez-Xicotencatl
- Centro de Investigación Sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México
| | - Yvonne Rosenstein
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Gustavo Pedraza-Alva
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
- * E-mail:
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Fu Q, Cash SE, Andersen JJ, Kennedy CR, Oldenburg DG, Zander VB, Foley GR, Simon Shelley C. CD43 in the nucleus and cytoplasm of lung cancer is a potential therapeutic target. Int J Cancer 2012; 132:1761-70. [PMID: 23015282 DOI: 10.1002/ijc.27873] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 08/31/2012] [Indexed: 12/27/2022]
Abstract
CD43 is a transmembrane sialoglycoprotein. Normally the molecule is only produced by white blood cells where it regulates functions such as intercellular adhesion, intracellular signaling, apoptosis, migration and proliferation. Two CD43 antibodies were used to interrogate 66 cases of non-small cell lung cancer (NSCLC) and 24 cases of small cell lung cancer (SCLC). In addition, we engineered the CD43-positive lung cancer cell line A549 to stably express either non-targeted or CD43-targeted small-interfering RNA (siRNA). These lines were then subjected to in vitro assays of apoptosis, natural killer (NK) cell cytotoxicity, intercellular adhesion and transendothelial migration. A xenograft mouse model evaluated the ability of the lines to grow primary tumors in vivo. CD43 was found to be expressed in the majority of both SCLC and NSCLC. Inclusive of CD43-negative tumors, differential patterns of nuclear and cytoplasmic expression of CD43 define four molecular subcategories of lung cancer. Targeting CD43 in A549 lung cancer cells, increased homotypic adhesion, decreased heterotypic adhesion and transendothelial migration, increased susceptibility to apoptosis and increased vulnerability to lysis by NK cells. Furthermore, targeting inhibited the growth of primary tumors in nude mice.
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Affiliation(s)
- Qiangwei Fu
- Department of Hematology/Oncology, Gundersen Medical Foundation, La Crosse, WI 54601, USA
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Abstract
The Alzheimer's disease (AD)-associated amyloid-β protein precursor (AβPP) is cleaved by α-, β-, and presenilin (PS)/γ-secretases through sequential regulated proteolysis. These proteolytic events control the generation of the pathogenic amyloid-β (Aβ) peptide, which excessively accumulates in the brains of individuals afflicted by AD. A growing number of additional proteins cleaved by PS/γ-secretase continue to be discovered. Similarly to AβPP, most of these proteins are type-I transmembrane proteins involved in vital signaling functions regulating cell fate, adhesion, migration, neurite outgrowth, or synaptogenesis. All the identified proteins share common structural features, which are typical for their proteolysis. The consequences of the PS/γ-secretase-mediated cleavage on the function of many of these proteins are largely unknown. Here, we review the current literature on the proteolytic processing mediated by the versatile PS/γ-secretase complex. We begin by discussing the steps of AβPP processing and PS/γ-secretase complex composition and localization, which give clues to how and where the processing of other PS/γ-secretase substrates may take place. Then we summarize the typical features of PS/γ-secretase-mediated protein processing. Finally, we recapitulate the current knowledge on the possible physiological function of PS/γ-secretase-mediated cleavage of specific substrate proteins.
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Affiliation(s)
- Annakaisa Haapasalo
- Institute of Clinical Medicine-Neurology, University of Eastern Finland, Kuopio, Finland.
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Pardossi-Piquard R, Checler F. The physiology of the β-amyloid precursor protein intracellular domain AICD. J Neurochem 2011; 120 Suppl 1:109-124. [PMID: 22122663 DOI: 10.1111/j.1471-4159.2011.07475.x] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The amyloid-β precursor protein (βAPP) undergoes several cleavages by enzymatic activities called secretases. Numerous studies aimed at studying the biogenesis and catabolic fate of Aβ peptides, the proteinaceous component of the senile plaques that accumulate in Alzheimer's disease-affected brains. Relatively recently, another secretase-mediated β-APP-derived catabolite called APP IntraCellular Domain (AICD) entered the game. Whether AICD corresponded to a biologically inert by-pass product of βAPP processing or whether it could harbor its own function remained questionable. In this study, we review the mechanisms by which AICD is generated and how its production is regulated. Furthermore, we discuss the degradation mechanism underlying its rapid catabolic fate. Finally, we review putative AICD-related functions and more particularly, the numerous studies indicating that AICD could translocate to the nucleus and control at a transcriptional level, the expression of a series of proteins involved in various functions including the control of cell death and Aβ degradation.
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Affiliation(s)
- Raphaëlle Pardossi-Piquard
- Université de Nice Sophia-Antipolis, Institut de Pharmacologie Moléculaire et Cellulaire UMR6097 CNRS, Equipe labellisée Fondation pour la Recherche Médicale, Sophia-Antipolis, Valbonne, France
| | - Frédéric Checler
- Université de Nice Sophia-Antipolis, Institut de Pharmacologie Moléculaire et Cellulaire UMR6097 CNRS, Equipe labellisée Fondation pour la Recherche Médicale, Sophia-Antipolis, Valbonne, France
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Cullen PJ. Post-translational regulation of signaling mucins. Curr Opin Struct Biol 2011; 21:590-6. [PMID: 21889329 DOI: 10.1016/j.sbi.2011.08.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Revised: 08/11/2011] [Accepted: 08/15/2011] [Indexed: 01/31/2023]
Abstract
Signaling mucins are large transmembrane glycoproteins that regulate signal transduction pathways. Recent advances have shown that two major types of post-translational modifications, protein glycosylation and proteolytic processing, play important and unexpected roles in regulating signaling mucin function. New O-glycosyltransferases and proteases have been identified, and the structure of the domain that undergoes auto-proteolysis has been solved. A picture is beginning to emerge where specific glycosyl modifications and regulated processing control the signaling and adherence properties of signaling glycoproteins and contribute to the routing of signals to specific pathways.
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Affiliation(s)
- Paul J Cullen
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, NY 14260-1300, United States.
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Wang X, Cowan JW, Gerhart M, Zelickson BR, Jiang J, He K, Wolfe MS, Black RA, Frank SJ. γ-Secretase-mediated growth hormone receptor proteolysis: Mapping of the intramembranous cleavage site. Biochem Biophys Res Commun 2011; 408:432-6. [DOI: 10.1016/j.bbrc.2011.04.041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Accepted: 04/08/2011] [Indexed: 11/27/2022]
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Saraiva LM, Seixas da Silva GS, Galina A, da-Silva WS, Klein WL, Ferreira ST, De Felice FG. Amyloid-β triggers the release of neuronal hexokinase 1 from mitochondria. PLoS One 2010; 5:e15230. [PMID: 21179577 PMCID: PMC3002973 DOI: 10.1371/journal.pone.0015230] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Accepted: 10/29/2010] [Indexed: 01/30/2023] Open
Abstract
Brain accumulation of the amyloid-β peptide (Aβ) and oxidative stress underlie neuronal dysfunction and memory loss in Alzheimer's disease (AD). Hexokinase (HK), a key glycolytic enzyme, plays important pro-survival roles, reducing mitochondrial reactive oxygen species (ROS) generation and preventing apoptosis in neurons and other cell types. Brain isozyme HKI is mainly associated with mitochondria and HK release from mitochondria causes a significant decrease in enzyme activity and triggers oxidative damage. We here investigated the relationship between Aβ-induced oxidative stress and HK activity. We found that Aβ triggered HKI detachment from mitochondria decreasing HKI activity in cortical neurons. Aβ oligomers further impair energy metabolism by decreasing neuronal ATP levels. Aβ-induced HKI cellular redistribution was accompanied by excessive ROS generation and neuronal death. 2-deoxyglucose blocked Aβ-induced oxidative stress and neuronal death. Results suggest that Aβ-induced cellular redistribution and inactivation of neuronal HKI play important roles in oxidative stress and neurodegeneration in AD.
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Affiliation(s)
- Leonardo M. Saraiva
- Programa de Bioquímica e Biofísica Celular, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Gisele S. Seixas da Silva
- Programa de Bioquímica e Biofísica Celular, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Antonio Galina
- Programa de Bioquímica e Biofísica Celular, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Wagner S. da-Silva
- Programa de Bioquímica e Biofísica Celular, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - William L. Klein
- Department of Neurobiology and Physiology, Northwestern University, Evanston, Illinois, United States of America
| | - Sérgio T. Ferreira
- Programa de Bioquímica e Biofísica Celular, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fernanda G. De Felice
- Programa de Bioquímica e Biofísica Celular, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
- Department of Neurobiology and Physiology, Northwestern University, Evanston, Illinois, United States of America
- * E-mail:
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Krishnaswamy S, Verdile G, Groth D, Kanyenda L, Martins RN. The structure and function of Alzheimer’s gamma secretase enzyme complex. Crit Rev Clin Lab Sci 2009; 46:282-301. [DOI: 10.3109/10408360903335821] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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15
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van Loo KMJ, van Schijndel JE, van Zweeden M, van Manen D, Trip MD, Petersen DC, Schuitemaker H, Hayes VM, Martens GJM. Correlation between HIV-1 seropositivity and prevalence of a gamma-secretase polymorphism in two distinct ethnic populations. J Med Virol 2009; 81:1847-51. [PMID: 19774691 DOI: 10.1002/jmv.21601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Susceptibility for human immunodeficiency virus type 1 (HIV-1) infection may be influenced by host genetics. Recent findings with a Wistar rat model raised the possibility that the gamma-secretase pathway may be associated with an individual's susceptibility to infection. A functional single-nucleotide polymorphism (SNP) in the gamma-secretase component APH1B (Phe217Leu; rs1047552) was therefore analyzed for association with HIV-1 infection. The SNP showed a tendency for association with HIV-1 infection in a Xhosa indigenous South African Bantu study (P = 0.087), and associated significantly in a Caucasian Dutch study (P = 0.049). Together, the results suggest a role for the gamma-secretase pathway in susceptibility to HIV-1 infection.
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Affiliation(s)
- Karen M J van Loo
- Department of Molecular Animal Physiology, Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour and Nijmegen Center for Molecular Life Sciences, Nijmegen 6525 GA , The Netherlands
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16
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CD43 processing and nuclear translocation of CD43 cytoplasmic tail are required for cell homeostasis. Blood 2009; 114:3567-77. [PMID: 19696198 DOI: 10.1182/blood-2009-06-228791] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The sialomucin CD43 is highly expressed on most hematopoietic cells. In this study, we show that the CD43 ectodomain is shed from murine granulocytes, mast cells, and T cells, but not from macrophages. To study the significance of CD43 shedding, we constructed 2 CD43/34 chimeras in which the CD43 membrane-proximal or transmembrane domain was swapped with the corresponding domain from CD34 that is not shed from cells. Viability of cells that normally shed CD43 was negatively affected when forced to express either of the 2 CD43/34 chimeras, but toxicity was reduced when cells coexpressed wild-type CD43. The CD43 cytoplasmic tail (CD43ct) was found to translocate into the nucleus, and inhibition of either its nuclear translocation or its release by gamma-secretase was proapoptotic. Involvement of CD43 in regulation of apoptosis is consistent with our findings that CD43ct was modified by small ubiquitin-like modifier-1 and was colocalized with promyelocytic nuclear bodies. CD43-deficient cells exhibited reduced levels of promyelocytic nuclear bodies and had increased sensitivity to apoptosis induced by growth factor withdrawal or T-regulatory cell suppression. Taken together, our data indicate an essential function of CD43 processing and nuclear localization of CD43ct in cell homeostasis and apoptosis.
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17
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Cole DC, Stock JR, Kreft AF, Antane M, Aschmies SH, Atchison KP, Casebier DS, Comery TA, Diamantidis G, Ellingboe JW, Harrison BL, Hu Y, Jin M, Kubrak DM, Lu P, Mann CW, Martone RL, Moore WJ, Oganesian A, Riddell DR, Sonnenberg-Reines J, Sun SC, Wagner E, Wang Z, Woller KR, Xu Z, Zhou H, Jacobsen JS. (S)-N-(5-Chlorothiophene-2-sulfonyl)-beta,beta-diethylalaninol a Notch-1-sparing gamma-secretase inhibitor. Bioorg Med Chem Lett 2008; 19:926-9. [PMID: 19097890 DOI: 10.1016/j.bmcl.2008.11.116] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2008] [Revised: 11/24/2008] [Accepted: 11/26/2008] [Indexed: 11/16/2022]
Abstract
Accumulation of beta-amyloid (Abeta), produced by the proteolytic cleavage of amyloid precursor protein (APP) by beta- and gamma-secretase, is widely believed to be associated with Alzheimer's disease (AD). Research around the high-throughput screening hit (S)-4-chlorophenylsulfonyl isoleucinol led to the identification of the Notch-1-sparing (9.5-fold) gamma-secretase inhibitor (S)-N-(5-chlorothiophene-2-sulfonyl)-beta,beta-diethylalaninol 7.b.2 (Abeta(40/42) EC(50)=28 nM), which is efficacious in reduction of Abeta production in vivo.
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Affiliation(s)
- Derek C Cole
- Chemical and Screening Sciences, Wyeth Research, Pearl River, NY 10965, USA.
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18
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Carpenter G, Liao HJ. Trafficking of receptor tyrosine kinases to the nucleus. Exp Cell Res 2008; 315:1556-66. [PMID: 18951890 DOI: 10.1016/j.yexcr.2008.09.027] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2008] [Revised: 09/17/2008] [Accepted: 09/19/2008] [Indexed: 12/23/2022]
Abstract
It has been known for at least 20 years that growth factors induce the internalization of cognate receptor tyrosine kinases (RTKs). The internalized receptors are then sorted to lysosomes or recycled to the cell surface. More recently, data have been published to indicate other intracellular destinations for the internalized RTKs. These include the nucleus, mitochondria, and cytoplasm. Also, it is recognized that trafficking to these novel destinations involves new biochemical mechanisms, such as proteolytic processing or interaction with translocons, and that these trafficking events have a function in signal transduction, implicating the receptor itself as a signaling element between the cell surface and the nucleus.
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Affiliation(s)
- Graham Carpenter
- Department of Biochemistry, Vanderbilt University Medical Center, Nashville, Tennessee 37232-0146, USA.
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19
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Mambole A, Baruch D, Nusbaum P, Bigot S, Suzuki M, Lesavre P, Fukuda M, Halbwachs-Mecarelli L. The cleavage of neutrophil leukosialin (CD43) by cathepsin G releases its extracellular domain and triggers its intramembrane proteolysis by presenilin/gamma-secretase. J Biol Chem 2008; 283:23627-35. [PMID: 18586676 DOI: 10.1074/jbc.m710286200] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The highly negatively charged membrane sialoglycoprotein leukosialin, CD43, is shed during neutrophil activation. This is generally thought to enhance cell adhesion. We here describe two novel consequences of this shedding, during neutrophil activation by phorbol esters or by chemoattractants after TNF-alpha priming. CD43 proteolysis was investigated by Western blotting, using a polyclonal antibody to CD43 intracellular domain. Our data emphasize the importance of a juxtamembranous cleavage of about 50% of membrane CD43 molecules by cathepsin G. Indeed, it is inhibited by alpha1-antichymotrypsin and cathepsin G inhibitor I and is reproduced by exogenous purified cathepsin G. The resulting membrane-anchored C-terminal fragment, CD43-CTF, becomes susceptible to presenilin/gamma-secretase, which releases CD43 intracytoplasmic domain: preincubation with three different gamma-secretase inhibitors, before PMN treatment by agonists or by purified cathepsin G, results in the accumulation of CD43-CTF. Because CD43 binds E-selectin, we also investigated the effect of the soluble extracellular domain CD43s, released by cathepsin G juxtamembranous cleavage, on neutrophil adhesion to endothelial cells. A recombinant CD43s-Fc fusion protein inhibited neutrophil E selectindependent adhesion to endothelial cells under flow conditions, while it had no effect on neutrophil static adhesion. We thus propose that, in addition to its potential pro-adhesive role, CD43 proteolysis results in: (i) the release, by cathepsin G, of CD43 extracellular domain, able to inhibit the adhesion of flowing neutrophils on endothelial cells and thus to participate to the natural control of inflammation; (ii) the release and/or the clearance, by presenilin/gamma-secretase, of CD43 intracellular domain, thereby regulating CD43-mediated signaling.
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Affiliation(s)
- Agnès Mambole
- INSERM U845, the Université René Descartes, Hôpital Necker, 161 Rue de Sèvres, Paris, France
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20
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Takai Y, Kitano K, Terawaki SI, Maesaki R, Hakoshima T. Structural basis of the cytoplasmic tail of adhesion molecule CD43 and its binding to ERM proteins. J Mol Biol 2008; 381:634-44. [PMID: 18614175 DOI: 10.1016/j.jmb.2008.05.085] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2008] [Revised: 05/29/2008] [Accepted: 05/31/2008] [Indexed: 11/24/2022]
Abstract
CD43/leukosialin/sialophorin is the major adhesion molecule in most hematopoietic cells and belongs to the sialomucin superfamily. In leukocyte emigration and activation, the exclusion of CD43 from the immunological synapse is an essential step. While the exclusion requires binding of the cytoplasmic region to ERM (ezrin/radixin/moesin) proteins, the detailed specific nature of the interaction between CD43 and ERM proteins is obscure. We have characterized the conformational properties of the CD43 cytoplasmic region, consisting of 124 amino acid residues, by hydrodynamic and spectroscopic measurements. Sedimentation equilibrium and velocity studies of ultracentrifugation revealed that the CD43 cytoplasmic peptide exists in a monomeric and extended form in solution. The crystal structure of the complex between the radixin FERM (4.1 and ERM) domain and the CD43 juxtamembrane region peptide reveals that the nonpolar region of the peptide binds subdomain C of the FERM domain. CD43 lacks the Motif-1 sequence for FERM binding found in the FERM-intercellular adhesion molecule-2 complex but possesses two conserved leucine residues that dock into the hydrophobic pocket of subdomain C without forming a 3(10)-helix. The FERM-binding site on CD43 is overlapped with the functional nuclear localization signal sequence. Our structure suggests that regulation of ERM binding may be coupled with regulated intramembrane proteolysis of CD43 followed by the nuclear transfer of the cytoplasmic peptide.
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Affiliation(s)
- Yumiko Takai
- Structural Biology Laboratory, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
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21
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Abstract
Gamma-Secretase is a promiscuous protease that cleaves bitopic membrane proteins within the lipid bilayer. Elucidating both the mechanistic basis of gamma-secretase proteolysis and the precise factors regulating substrate identification is important because modulation of this biochemical degradative process can have important consequences in a physiological and pathophysiological context. Here, we briefly review such information for all major classes of intramembranously cleaving proteases (I-CLiPs), with an emphasis on gamma-secretase, an I-CLiP closely linked to the etiology of Alzheimer's disease. A large body of emerging data allows us to survey the substrates of gamma-secretase to ascertain the conformational features that predispose a peptide to cleavage by this enigmatic protease. Because substrate specificity in vivo is closely linked to the relative subcellular compartmentalization of gamma-secretase and its substrates, we also survey the voluminous body of literature concerning the traffic of gamma-secretase and its most prominent substrate, the amyloid precursor protein.
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Affiliation(s)
- A. J. Beel
- Department of Biochemistry and Center for Structural Biology, Vanderbilt University School of Medicine, Rm. 5142 MRBIII, 21st Ave. S., Nashville, Tennessee 37232-8725 USA
| | - C. R. Sanders
- Department of Biochemistry and Center for Structural Biology, Vanderbilt University School of Medicine, Rm. 5142 MRBIII, 21st Ave. S., Nashville, Tennessee 37232-8725 USA
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22
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Takai Y, Kitano K, Terawaki SI, Maesaki R, Hakoshima T. Structural basis of PSGL-1 binding to ERM proteins. Genes Cells 2007; 12:1329-38. [DOI: 10.1111/j.1365-2443.2007.01137.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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23
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24
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Carey B, Kim D, Kovacs D. Presenilin/gamma-secretase and alpha-secretase-like peptidases cleave human MHC Class I proteins. Biochem J 2007; 401:121-7. [PMID: 17150042 PMCID: PMC1698663 DOI: 10.1042/bj20060847] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
HLA (human leucocyte antigen)-A2 is an MHC Class I protein with primary functions in T-cell development and initi-ation of immune cell responses. MHC I proteins also play roles in intercellular adhesion, apoptosis, cell proliferation and neuronal plasticity. By utilizing a sequence comparison analysis, we recently identified HLA-A2 as a potential substrate for the Alzheimer's disease-associated PS1 (presenilin 1)/gamma-secretase. alpha-Secretase-like membrane metalloproteinases are responsible for an initial shedding event, partially mediated by ADAM (a disinteg-rin and metalloproteinase)-10. Accordingly, activation or inhibition of alpha-secretase-like membrane metalloproteinases directly modulated levels of a 14 kDa HLA-A2 CTF (C-terminal frag-ment) in CHO (Chinese-hamster ovary) cells. To show that the HLA-A2 CTF is subsequently cleaved by PS1/gamma-secretase, we re-duced its activity in cell lines stably expressing HLA-A2 and in Jurkat T-cells expressing endogenous MHC I. Treatment with specific PS1/gamma-secretase inhibitors or expression of a dominant-negative construct led to a significant accumulation of HLA-A2 CTFs. We also identified the PS1/gamma-secretase cleavage product of HLA-A2 CTF, termed HLA-A2 intracellular domain, in cell-free and cell-based experiments. In the absence of proteasome inhibitors, HLA-A2 intracellular domain underwent rapid degrad-ation. These data indicate that MHC I proteins undergo extra-cellular domain cleavage mediated by alpha-secretases and the cleavage product is subsequently cleaved by PS1/gamma-secretase.
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Affiliation(s)
- Bryce W. Carey
- Neurobiology of Disease Laboratory, Genetics and Aging Research Unit/MIND, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 114 16th St., Charlestown, MA 02129, U.S.A
| | - Doo Y. Kim
- Neurobiology of Disease Laboratory, Genetics and Aging Research Unit/MIND, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 114 16th St., Charlestown, MA 02129, U.S.A
| | - Dora M. Kovacs
- Neurobiology of Disease Laboratory, Genetics and Aging Research Unit/MIND, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 114 16th St., Charlestown, MA 02129, U.S.A
- To whom correspondence should be addressed (email )
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25
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Evin G, Sernee MF, Masters CL. Inhibition of gamma-secretase as a therapeutic intervention for Alzheimer's disease: prospects, limitations and strategies. CNS Drugs 2006; 20:351-72. [PMID: 16696577 DOI: 10.2165/00023210-200620050-00002] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Genetic and experimental evidence points to amyloid-beta (Abeta) peptide as the culprit in Alzheimer's disease pathogenesis. This protein fragment abnormally accumulates in the brain cortex and hippocampus of patients with Alzheimer's disease, and self-aggregates to form toxic oligomers causing neurodegeneration.Abeta is heterogeneous and produced from a precursor protein (amyloid precursor protein [APP]) by two sequential proteolytic cleavages that involve beta- and gamma-secretases. This latter enzyme represents a potentially attractive drug target since it dictates the solubility of the generated Abeta fragment by creating peptides of various lengths, namely Abeta(40) and Abeta(42), the longest being the most aggregating. gamma-Secretase comprises a molecular complex of four integral membrane proteins - presenilin, nicastrin, APH-1 and PEN-2 - and its molecular mechanism remains under extensive scrutiny. The ratio of Abeta(42) over Abeta(40) is increased by familial Alzheimer's disease mutations occurring in the presenilin genes or in APP, near the gamma-secretase cleavage site. Potent gamma-secretase inhibitors have been identified by screening drug libraries or by designing aspartyl protease transition-state analogues based on the APP substrate cleavage site. Most of these compounds are not specific for gamma-secretase cleavage of APP, and equally inhibit the processing of other gamma-secretase substrates, such as Notch and a subset of cell-surface receptors and proteins involved in embryonic development, haematopoiesis, cell adhesion and cell/cell contacts. Therefore, current research aims at finding compounds that show selectivity for APP cleavage, and particularly that inhibit the formation of the aggregating form, Abeta(42). Compounds that target the substrate docking site rather than the enzyme active site are also being investigated as an alternative strategy. The finding that some NSAID analogues preferentially inhibit the formation of Abeta(42) over Abeta(40) and do not affect Notch processing has opened a new therapeutic window. The progress in design of selective inhibitors as well as recent results obtained in animal studies prove that gamma-secretase remains among the best targets for the therapeutic control of amyloid build-up in Alzheimer's disease. The full understanding of gamma-secretase regulation may yet uncover new therapeutic leads.
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Affiliation(s)
- Geneviève Evin
- Department of Pathology, The University of Melbourne, Parkville, Victoria, Australia.
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26
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Vetrivel KS, Zhang YW, Xu H, Thinakaran G. Pathological and physiological functions of presenilins. Mol Neurodegener 2006; 1:4. [PMID: 16930451 PMCID: PMC1513131 DOI: 10.1186/1750-1326-1-4] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2006] [Accepted: 06/12/2006] [Indexed: 11/16/2022] Open
Abstract
Mutations in PSEN1 and PSEN2 genes account for the majority of cases of early-onset familial Alzheimer disease. Since the first prediction of a genetic link between PSEN1 and PSEN2 with Alzheimer's disease, many research groups from both academia and pharmaceutical industry have sought to unravel how pathogenic mutations in PSEN cause presenile dementia. PSEN genes encode polytopic membrane proteins termed presenilins (PS1 and PS2), which function as the catalytic subunit of γ-secretase, an intramembrane protease that has a wide spectrum of type I membrane protein substrates. Sequential cleavage of amyloid precursor protein by BACE and γ-secretase releases highly fibrillogenic β-amyloid peptides, which accumulate in the brains of aged individuals and patients with Alzheimer's disease. Familial Alzheimer's disease-associated presenilin variants are thought to exert their pathogenic function by selectively elevating the levels of highly amyloidogenic Aβ42 peptides. In addition to Alzheimer's disease, several recent studies have linked PSEN1 to familiar frontotemporal dementia. Here, we review the biology of PS1, its role in γ-secretase activity, and discuss recent developments in the cell biology of PS1 with respect to Alzheimer's disease pathogenesis.
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Affiliation(s)
- Kulandaivelu S Vetrivel
- Department of Neurobiology, Pharmacology and Physiology, The University of Chicago, Chicago, IL 60637, USA
| | - Yun-wu Zhang
- Center for Neuroscience and Aging, Burnham Institute for Medical Research, LaJolla, CA 92037, USA
| | - Huaxi Xu
- Center for Neuroscience and Aging, Burnham Institute for Medical Research, LaJolla, CA 92037, USA
| | - Gopal Thinakaran
- Department of Neurobiology, Pharmacology and Physiology, The University of Chicago, Chicago, IL 60637, USA
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27
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Nyborg AC, Ladd TB, Zwizinski CW, Lah JJ, Golde TE. Sortilin, SorCS1b, and SorLA Vps10p sorting receptors, are novel gamma-secretase substrates. Mol Neurodegener 2006; 1:3. [PMID: 16930450 PMCID: PMC1513133 DOI: 10.1186/1750-1326-1-3] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2006] [Accepted: 06/12/2006] [Indexed: 11/30/2022] Open
Abstract
Background The mammalian Vps10p sorting receptor family is a group of 5 type I membrane homologs (Sortilin, SorLA, and SorCS1-3). These receptors bind various cargo proteins via their luminal Vps10p domains and have been shown to mediate a variety of intracellular sorting and trafficking functions. These proteins are highly expressed in the brain. SorLA has been shown to be down regulated in Alzheimer's disease brains, interact with ApoE, and modulate Aβ production. Sortilin has been shown to be part of proNGF mediated death signaling that results from a complex of Sortilin, p75NTR and proNGF. We have investigated and provide evidence for γ-secretase cleavage of this family of proteins. Results We provide evidence that these receptors are substrates for presenilin dependent γ-secretase cleavage. γ-Secretase cleavage of these sorting receptors is inhibited by γ-secretase inhibitors and does not occur in PS1/PS2 knockout cells. Like most γ-secretase substrates, we find that ectodomain shedding precedes γ-secretase cleavage. The ectodomain cleavage is inhibited by a metalloprotease inhibitor and activated by PMA suggesting that it is mediated by an α-secretase like cleavage. Conclusion These data indicate that the α- and γ-secretase cleavages of the mammalian Vps10p sorting receptors occur in a fashion analogous to other known γ-secretase substrates, and could possibly regulate the biological functions of these proteins.
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Affiliation(s)
- Andrew C Nyborg
- Department of Neuroscience, Mayo Clinic Jacksonville, Mayo Clinic College of Medicine, 4500 San Pablo Road, Jacksonville, Florida 32224, USA
| | - Thomas B Ladd
- Department of Neuroscience, Mayo Clinic Jacksonville, Mayo Clinic College of Medicine, 4500 San Pablo Road, Jacksonville, Florida 32224, USA
| | - Craig W Zwizinski
- Department of Neuroscience, Mayo Clinic Jacksonville, Mayo Clinic College of Medicine, 4500 San Pablo Road, Jacksonville, Florida 32224, USA
| | - James J Lah
- Department of Neurology, Center for Neurodegenerative Disease, Emory University, Whitehead Biomedical Research Building, 615 Michael Street, Suite 505, Atlanta, GA 30322, USA
| | - Todd E Golde
- Department of Neuroscience, Mayo Clinic Jacksonville, Mayo Clinic College of Medicine, 4500 San Pablo Road, Jacksonville, Florida 32224, USA
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